Hello: Well head gaskets can fail in several ways. One failure is that the oil passage and water passage can get hooked together, then oil gets into the water and water gets into the oil. The oil will usually change colors, get sort of white looking, thats bad. Matbe will see oil slick signs where the water is poured into the radiator. Another way is a cylinder leak into the water jacket. Depending on the nature of the failure it may act like a one way valve, Only compression into the water, but water not into the cylinder. If you have this type of failure usually the enging will get hot quick and be difficult to keep it cool no matter what you do. By removing the radiator cap and keepong it topped off with a hose running slowly watch for air bubbles coming out of the radiator. This is pecause the leaking cylinder is pushing air into the water jacket. Sometimes a compression check will show the faulty cylinder if it is a cylinder seal type failure. A water jacket to oil gallery failure a compression check will not show that failure. There are several other tests that can help determine, but those are the easiest
good luck
Darryl.
Wednesday, January 18th, 2006 AT 9:26 PM